BBB failure to boot, due to our cape.

GoogleGroups
1

Cc'd to the BBB group as well

Where can we fond the code to the Boot Rom? For the next revision of our cape, I will be fixing the enable, I am aware of this, the power too the level shifters was to be enabled via the SYS_RESETN, but it has caused other issues, so now it is hard connected via a jumper.

There are only a few of these capes for development purposes, so we would like to modify the ROM to allow for this on these capes.

There will be further changes to revision 2 of the cape, but before that, I need to allow development to continue, regardless of hardware issues

For this application, being an autopilot, we are going for a fixed configuration, so we do not have any unexpected behaviour during flight, due to user configuration changes.

Thanks

Philip

2

Cc'd to the BBB group as well

Where can we fond the code to the Boot Rom? For the next revision of our cape, I will be fixing the enable, I am aware of this, the power too the level shifters was to be enabled via the SYS_RESETN, but it has caused other issues, so now it is hard connected via a jumper.

There are only a few of these capes for development purposes, so we would like to modify the ROM to allow for this on these capes.

In case it the name "ROM" wasn't clear: "ROM" = "Read only Memory"
Fix your cape...

There will be further changes to revision 2 of the cape, but before that, I need to allow development to continue, regardless of hardware issues

For this application, being an autopilot, we are going for a fixed configuration, so we do not have any unexpected behaviour during flight, due to user configuration changes.

Regards,

3

I am aware that Rom means read only.
I am aware that I need to fix the cape on the next revision

My question
Is the ROM, hard coded silicone? OTP? Or JTAG flashed, all of which are commonly referred to as ROM.

The time to spin new hardware is longer than the GSOC students have to do their projects, so I am looking for a short term fix.

If it is hard coded, I will have no choice but to spin new hardware, that's the question

4

http://processors.wiki.ti.com/index.php/Boot_Sequence

"At power-up an OMAP3 device begins booting from internal Boot ROM.
This code is fixed during the manufacturing process and cannot be
altered."

aka.. classic definition of 'rom'

Regards,

5

Hi All
i read up on the ROM boot code, and it’s masked. we can’t make changes to it at all.
http://tara.mmto.org/computers/beagle/uboot.html
we have the address, etc. of the place where the ROM boot loader is, but we won’t be able to make changes to it.
also, this discussion on the ti forum http://e2e.ti.com/support/arm/sitara_arm/f/791/t/158347.aspx
so ROM → MLO → U-Boot. and only the last 2 can be edited.

6

Yes, I confirmed that it is ROM in the true silicone sense… So I will look to see what I can do in hardware to get things moving… Will send a fix out to you all soon

Philip Rowse
Electrical Engineering Department
3DRobotics
Ballarat
Australia